Answer:
The final velocity is 28.14 m/s
Yes the angle of projection matters
Explanation:
Given;
initial velocity of the water balloon, u = 20 m/s
height of the building, h = 20 m
let the final speed of the ball when it hits the ground = v
The final speed is calculated as follows;
v² = u² + 2gh
v² = (20)² + 2(9.8)(20)
v² = 400 + 392
v² = 792
v = √792
v = 28.14 m/s
Yes the angle matters, if the balloon had been dropped at a certain angle, the final velocity would have been estimated using the following formula;
where;
θ is the angle of projection, which accounts for the vertical component of the velocity.
Answer:
Explanation:
r = 60 mph
d = 100 miles
t = ?
t = d/r
t = 100 /60
t = 1 2/3 hour or 1 hour and 40 minutes.
Answer:
28,400 N
Explanation:
Let's start by calculating the pressure that acts on the upper surface of the hatch. It is given by the sum of the atmospheric pressure and the pressure due to the columb of water, which is given by Stevin's law:
On the lower part of the hatch, there is a pressure equal to
So, the net pressure acting on the hatch is
which acts from above.
The area of the hatch is given by:
So, the force needed to open the hatch from the inside is equal to the pressure multiplied by the area of the hatch:
Answer:
s = 3 m
Explanation:
Let t be the time the accelerating car starts.
Let's assume the vehicles are point masses so that "passing" takes no time.
the position of the constant velocity and accelerating vehicles are
s = vt = 40(t + 2) cm
s = ½at² = ½(20)(t)² cm
they pass when their distance is the same
½(20)(t)² = 40(t + 2)
10t² = 40t + 80
0 = 10t² - 40t - 80
0 = t² - 4t - 8
t = (4±√(4² - 4(1)(-8))) / 2(1)
t = (4± 6.928) / 2 ignore the negative time as it has not occurred yet.
t = 5.464 s
s = 40(5.464 + 2) = 298.564 cm
300 cm when rounded to the single significant digit of the question numerals.
A snowball picks up speed as it rolls down the mountain.<em> (D)</em>
Since the description includes acceleration ("picks up speed"), we know that the forces on the snowball must be unbalanced.
